The Inertial Stellar Compass: A New Direction in Spacecraft Attitude Determination

Abstract

The Inertial Stellar Compass (ISC) is a real-time, miniature, lowpower stellar inertial attitude determination system, composed of a wide field-of-view (WFOV) active pixel star camera and a microelectromechanical system (MEMS) gyro assembly, with associated processing and power electronics. The integrated technologies enable an attitude determination system with an accuracy of 0.1 deg (1σ) to be realized at very low power and volume. The attitude knowledge provided by the ISC is applicable to a wide range of space and earth science missions that may include the use of highly maneuverable, stabilized, tumbling, or lost spacecraft. Under the guidance of NASA’s New Millennium ST-6 project, Draper Laboratory is currently developing the ISC. Its completion and flight validation will represent a breakthrough in real-time miniature attitude determination sensors. This paper describes system design, development, and validation activities currently underway at Draper.